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-rw-r--r--arch/i386/kernel/hpet.c150
1 files changed, 106 insertions, 44 deletions
diff --git a/arch/i386/kernel/hpet.c b/arch/i386/kernel/hpet.c
index e1006b7acc9e..17d73459fc5f 100644
--- a/arch/i386/kernel/hpet.c
+++ b/arch/i386/kernel/hpet.c
@@ -3,6 +3,8 @@
#include <linux/errno.h>
#include <linux/hpet.h>
#include <linux/init.h>
+#include <linux/sysdev.h>
+#include <linux/pm.h>
#include <asm/hpet.h>
#include <asm/io.h>
@@ -197,16 +199,34 @@ static int hpet_next_event(unsigned long delta,
cnt += delta;
hpet_writel(cnt, HPET_T0_CMP);
- return ((long)(hpet_readl(HPET_COUNTER) - cnt ) > 0);
+ return ((long)(hpet_readl(HPET_COUNTER) - cnt ) > 0) ? -ETIME : 0;
}
/*
+ * Clock source related code
+ */
+static cycle_t read_hpet(void)
+{
+ return (cycle_t)hpet_readl(HPET_COUNTER);
+}
+
+static struct clocksource clocksource_hpet = {
+ .name = "hpet",
+ .rating = 250,
+ .read = read_hpet,
+ .mask = HPET_MASK,
+ .shift = HPET_SHIFT,
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+/*
* Try to setup the HPET timer
*/
int __init hpet_enable(void)
{
unsigned long id;
uint64_t hpet_freq;
+ u64 tmp;
if (!is_hpet_capable())
return 0;
@@ -253,6 +273,25 @@ int __init hpet_enable(void)
/* Start the counter */
hpet_start_counter();
+ /* Initialize and register HPET clocksource
+ *
+ * hpet period is in femto seconds per cycle
+ * so we need to convert this to ns/cyc units
+ * aproximated by mult/2^shift
+ *
+ * fsec/cyc * 1nsec/1000000fsec = nsec/cyc = mult/2^shift
+ * fsec/cyc * 1ns/1000000fsec * 2^shift = mult
+ * fsec/cyc * 2^shift * 1nsec/1000000fsec = mult
+ * (fsec/cyc << shift)/1000000 = mult
+ * (hpet_period << shift)/FSEC_PER_NSEC = mult
+ */
+ tmp = (u64)hpet_period << HPET_SHIFT;
+ do_div(tmp, FSEC_PER_NSEC);
+ clocksource_hpet.mult = (u32)tmp;
+
+ clocksource_register(&clocksource_hpet);
+
+
if (id & HPET_ID_LEGSUP) {
hpet_enable_int();
hpet_reserve_platform_timers(id);
@@ -270,52 +309,10 @@ int __init hpet_enable(void)
out_nohpet:
iounmap(hpet_virt_address);
hpet_virt_address = NULL;
+ boot_hpet_disable = 1;
return 0;
}
-/*
- * Clock source related code
- */
-static cycle_t read_hpet(void)
-{
- return (cycle_t)hpet_readl(HPET_COUNTER);
-}
-
-static struct clocksource clocksource_hpet = {
- .name = "hpet",
- .rating = 250,
- .read = read_hpet,
- .mask = HPET_MASK,
- .shift = HPET_SHIFT,
- .flags = CLOCK_SOURCE_IS_CONTINUOUS,
-};
-
-static int __init init_hpet_clocksource(void)
-{
- u64 tmp;
-
- if (!hpet_virt_address)
- return -ENODEV;
-
- /*
- * hpet period is in femto seconds per cycle
- * so we need to convert this to ns/cyc units
- * aproximated by mult/2^shift
- *
- * fsec/cyc * 1nsec/1000000fsec = nsec/cyc = mult/2^shift
- * fsec/cyc * 1ns/1000000fsec * 2^shift = mult
- * fsec/cyc * 2^shift * 1nsec/1000000fsec = mult
- * (fsec/cyc << shift)/1000000 = mult
- * (hpet_period << shift)/FSEC_PER_NSEC = mult
- */
- tmp = (u64)hpet_period << HPET_SHIFT;
- do_div(tmp, FSEC_PER_NSEC);
- clocksource_hpet.mult = (u32)tmp;
-
- return clocksource_register(&clocksource_hpet);
-}
-
-module_init(init_hpet_clocksource);
#ifdef CONFIG_HPET_EMULATE_RTC
@@ -527,3 +524,68 @@ irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id)
return IRQ_HANDLED;
}
#endif
+
+
+/*
+ * Suspend/resume part
+ */
+
+#ifdef CONFIG_PM
+
+static int hpet_suspend(struct sys_device *sys_device, pm_message_t state)
+{
+ unsigned long cfg = hpet_readl(HPET_CFG);
+
+ cfg &= ~(HPET_CFG_ENABLE|HPET_CFG_LEGACY);
+ hpet_writel(cfg, HPET_CFG);
+
+ return 0;
+}
+
+static int hpet_resume(struct sys_device *sys_device)
+{
+ unsigned int id;
+
+ hpet_start_counter();
+
+ id = hpet_readl(HPET_ID);
+
+ if (id & HPET_ID_LEGSUP)
+ hpet_enable_int();
+
+ return 0;
+}
+
+static struct sysdev_class hpet_class = {
+ set_kset_name("hpet"),
+ .suspend = hpet_suspend,
+ .resume = hpet_resume,
+};
+
+static struct sys_device hpet_device = {
+ .id = 0,
+ .cls = &hpet_class,
+};
+
+
+static __init int hpet_register_sysfs(void)
+{
+ int err;
+
+ if (!is_hpet_capable())
+ return 0;
+
+ err = sysdev_class_register(&hpet_class);
+
+ if (!err) {
+ err = sysdev_register(&hpet_device);
+ if (err)
+ sysdev_class_unregister(&hpet_class);
+ }
+
+ return err;
+}
+
+device_initcall(hpet_register_sysfs);
+
+#endif